Rock hounding locations near San Francisco,Bay Area

Does anybody know of any rock hounding places anywhere near the San Francisco Bay Area within about 150 to 250 mile radius?

Chuck,

One of my favorite collecting spots is the Laytonville Quarry which sits beside HW 101 about 150 miles north of San Francisco. Aside from the unique mineral assemblage here, you can observe blueschist grade metamorphism. To top it off, there is a convenient pull off on the west side of the highway from the quarry. Material is readily at hand, though a crack hammer and chisel does come in handy.

South of Clear Lake along Soda Bay Road a few hundred yards from the intersection with HW 29 is a nice spot to collect obsidian. Wear gloves though, some of the pieces will slice your fingers.

If ecologite interests you, then Sykes Rock is a good spot. Take HW 162 at Longvale for 3.5 miles. There is a house sized block of eclogite along the side of the road. Along the small creek on the other side of the eclogite are boulders of peridotite.

Hope this helps. There are more places, just haven't found them yet.